BACKGROUND While colon endoscopic mucosal resection(EMR)is an effective technique,removal of larger polyps often requires piecemeal resection,which can increase recurrence rates.Endoscopic submucosal dissection(ESD)in...BACKGROUND While colon endoscopic mucosal resection(EMR)is an effective technique,removal of larger polyps often requires piecemeal resection,which can increase recurrence rates.Endoscopic submucosal dissection(ESD)in the colon offers the ability for en bloc resection and is well-described in Asia,but there are limited studies comparing ESD vs EMR in the West.AIM To evaluate different techniques in endoscopic resection of large polyps in the colon and to identify factors for recurrence.METHODS The study is a retrospective comparison of ESD,EMR and knife-assisted endoscopic resection performed at Stanford University Medical Center and Veterans Affairs Palo Alto Health Care System between 2016 and 2020.Knife-assisted endoscopic resection was defined as use of electrosurgical knife to facilitate snare resection,such as for circumferential incision.Patients≥18 years of age undergoing colonoscopy with removal of polyp(s)≥20 mm were included.The primary outcome was recurrence on follow-up.RESULTS A total of 376 patients and 428 polyps were included.Mean polyp size was greatest in the ESD group(35.8 mm),followed by knife-assisted endoscopic resection(33.3 mm)and EMR(30.5 mm)(P<0.001).ESD achieved highest en bloc resection(90.4%)followed by knife-assisted endoscopic resection(31.1%)and EMR(20.2%)(P<0.001).A total of 287 polyps had follow-up(67.1%).On follow-up analysis,recurrence rate was lowest in knife-assisted endoscopic resection(0.0%)and ESD(1.3%)and highest in EMR(12.9%)(P=0.0017).En bloc polyp resection had significantly lower rate of recurrence(1.9%)compared to non-en bloc(12.0%,P=0.003).On multivariate analysis,ESD(in comparison to EMR)adjusted for polyp size was found to significantly reduce risk of recurrence[adjusted hazard ratio 0.06(95%CI:0.01-0.57,P=0.014)].CONCLUSION In our study,EMR had significantly higher recurrence compared to ESD and knife-assisted endoscopic resection.We found factors including resection by ESD,en bloc removal,and use of circumferential incision were associated with significantly decreased recurrence.While further studies are needed,we have demonstrated the efficacy of ESD in a Western population.展开更多
Endoscopic ultrasonography(EUS) has become a useful diagnostic and therapeutic modality in gastrointestinal endoscopy.However,EUS requires additional training since it requires simultaneous endoscopic manipulation and...Endoscopic ultrasonography(EUS) has become a useful diagnostic and therapeutic modality in gastrointestinal endoscopy.However,EUS requires additional training since it requires simultaneous endoscopic manipulation and ultrasonographic interpretation.Obtaining adequate EUS training can be challenging since EUS is highly operator-dependent and training on actual patients can be associated with an increased risk of complications including inaccurate diagnosis.Therefore,several models have been developed to help facilitate training of EUS.The models currently available for EUS training include computer-based simulators,phantoms,ex vivo models,and live animal models.Although each model has its own merits and limitations,the value of these different models is rather complementary than competitive.However,there is a lack of objective data regarding the efficacy of each model with recommendations on the use of various training models based on expert opinion only.Therefore,objective studies evaluating the efficacy of various EUS training models on technical and clinical outcomes are still needed.展开更多
Gastroparesis, or symptomatic delayed gastric emptying in the absence of mechanical obstruction, is a challenging and increasingly identified syndrome. Medical options are limited and the only medication approved by t...Gastroparesis, or symptomatic delayed gastric emptying in the absence of mechanical obstruction, is a challenging and increasingly identified syndrome. Medical options are limited and the only medication approved by the Food and Drug Administration for treatment of gastroparesis is metoclopramide, although other agents are frequently used off label. With this caveat, first-line treatments for gastroparesis include dietary modifications, antiemetics and promotility agents, although these therapies are limited by suboptimal efficacy and significant medication side effects. Treatment of patients that fail first-line treatments represents a significant therapeutic challenge. Recent advances in endoscopic techniques have led to the development of a promising novel endoscopic therapy for gastroparesis via endoscopic pyloromyotomy, also referred to as gastric per-oral endoscopic myotomy or per-oral endoscopic pyloromyotomy. The aim of this article is to review the technical aspects of the per-oral endoscopic myotomy procedure for the treatment of gastroparesis, provide an overview of the currently published literature, and outline potential next directions for the field.展开更多
BACKGROUND The robust fibroinflammatory stroma characteristic of pancreatic ductal adenocarcinoma(PDA)impedes effective drug delivery.Pulsed focused ultrasound(pFUS)can disrupt this stroma and has improved survival in...BACKGROUND The robust fibroinflammatory stroma characteristic of pancreatic ductal adenocarcinoma(PDA)impedes effective drug delivery.Pulsed focused ultrasound(pFUS)can disrupt this stroma and has improved survival in an early clinical trial.Non-invasive methods to characterize pFUS treatment effects are desirable for advancement of this promising treatment modality in larger clinical trials.AIM To identify promising,non-invasive pre-clinical imaging methods to characterize acute pFUS treatment effects for in vivo models of PDA.METHODS We utilized quantitative magnetic resonance imaging methods at 14 tesla in three mouse models of PDA(subcutaneous,orthotopic and transgenic-KrasLSLG12D/+,Trp53LSL-R172H/+,Cre or“KPC”)to assess immediate tumor response to pFUS treatment(VIFU 2000 Alpinion Medical Systems;475 W peak electric power,1 ms pulse duration,1 Hz,duty cycle 0.1%)vs sham therapy,and correlated our results with histochemical data.These pFUS treatment parameters were previously shown to enhance tumor permeability to chemotherapeutics.T1 and T2 relaxation maps,high(126,180,234,340,549)vs low(7,47,81)b-value apparent diffusion coefficient(ADC)maps,magnetization transfer ratio(MTR)maps,and chemical exchange saturation transfer(CEST)maps for the amide proton spectrum(3.5 parts per million or“ppm”)and the glycosaminoglycan spectrum(0.5-1.5 ppm)were generated and analyzed pre-treatment,and immediately post-treatment,using ImageJ.Animals were sacrificed immediately following post-treatment imaging.The whole-tumor was selected as the region of interest for data analysis and subsequent statistical analysis.T-tests and Pearson correlation were used for statistical inference.RESULTS Mean high-b value ADC measurements increased significantly with pFUS treatment for all models.Mean glycosaminoglycan CEST and T2 measurements decreased significantly post-treatment for the KPC group.Mean MTR and amide CEST values increased significantly for the KPC group.Hyaluronic acid focal intensities in the treated regions were significantly lower following pFUS treatment for all animal models.The magnetic resonance imaging changes observed acutely following pFUS therapy likely reflect:(1)Sequelae of variable degrees of microcapillary hemorrhage(T1,MTR and amide CEST);(2)Lower PDA glycosaminoglycan content and associated water content(glycosaminoglycan CEST,T2 and hyaluronic acid focal intensity);and(3)Improved tumor diffusivity(ADC)post pFUS treatment.CONCLUSION T2,glycosaminoglycan CEST,and ADC maps may provide reliable quantitation of acute pFUS treatment effects for patients with PDA.展开更多
文摘BACKGROUND While colon endoscopic mucosal resection(EMR)is an effective technique,removal of larger polyps often requires piecemeal resection,which can increase recurrence rates.Endoscopic submucosal dissection(ESD)in the colon offers the ability for en bloc resection and is well-described in Asia,but there are limited studies comparing ESD vs EMR in the West.AIM To evaluate different techniques in endoscopic resection of large polyps in the colon and to identify factors for recurrence.METHODS The study is a retrospective comparison of ESD,EMR and knife-assisted endoscopic resection performed at Stanford University Medical Center and Veterans Affairs Palo Alto Health Care System between 2016 and 2020.Knife-assisted endoscopic resection was defined as use of electrosurgical knife to facilitate snare resection,such as for circumferential incision.Patients≥18 years of age undergoing colonoscopy with removal of polyp(s)≥20 mm were included.The primary outcome was recurrence on follow-up.RESULTS A total of 376 patients and 428 polyps were included.Mean polyp size was greatest in the ESD group(35.8 mm),followed by knife-assisted endoscopic resection(33.3 mm)and EMR(30.5 mm)(P<0.001).ESD achieved highest en bloc resection(90.4%)followed by knife-assisted endoscopic resection(31.1%)and EMR(20.2%)(P<0.001).A total of 287 polyps had follow-up(67.1%).On follow-up analysis,recurrence rate was lowest in knife-assisted endoscopic resection(0.0%)and ESD(1.3%)and highest in EMR(12.9%)(P=0.0017).En bloc polyp resection had significantly lower rate of recurrence(1.9%)compared to non-en bloc(12.0%,P=0.003).On multivariate analysis,ESD(in comparison to EMR)adjusted for polyp size was found to significantly reduce risk of recurrence[adjusted hazard ratio 0.06(95%CI:0.01-0.57,P=0.014)].CONCLUSION In our study,EMR had significantly higher recurrence compared to ESD and knife-assisted endoscopic resection.We found factors including resection by ESD,en bloc removal,and use of circumferential incision were associated with significantly decreased recurrence.While further studies are needed,we have demonstrated the efficacy of ESD in a Western population.
文摘Endoscopic ultrasonography(EUS) has become a useful diagnostic and therapeutic modality in gastrointestinal endoscopy.However,EUS requires additional training since it requires simultaneous endoscopic manipulation and ultrasonographic interpretation.Obtaining adequate EUS training can be challenging since EUS is highly operator-dependent and training on actual patients can be associated with an increased risk of complications including inaccurate diagnosis.Therefore,several models have been developed to help facilitate training of EUS.The models currently available for EUS training include computer-based simulators,phantoms,ex vivo models,and live animal models.Although each model has its own merits and limitations,the value of these different models is rather complementary than competitive.However,there is a lack of objective data regarding the efficacy of each model with recommendations on the use of various training models based on expert opinion only.Therefore,objective studies evaluating the efficacy of various EUS training models on technical and clinical outcomes are still needed.
文摘Gastroparesis, or symptomatic delayed gastric emptying in the absence of mechanical obstruction, is a challenging and increasingly identified syndrome. Medical options are limited and the only medication approved by the Food and Drug Administration for treatment of gastroparesis is metoclopramide, although other agents are frequently used off label. With this caveat, first-line treatments for gastroparesis include dietary modifications, antiemetics and promotility agents, although these therapies are limited by suboptimal efficacy and significant medication side effects. Treatment of patients that fail first-line treatments represents a significant therapeutic challenge. Recent advances in endoscopic techniques have led to the development of a promising novel endoscopic therapy for gastroparesis via endoscopic pyloromyotomy, also referred to as gastric per-oral endoscopic myotomy or per-oral endoscopic pyloromyotomy. The aim of this article is to review the technical aspects of the per-oral endoscopic myotomy procedure for the treatment of gastroparesis, provide an overview of the currently published literature, and outline potential next directions for the field.
基金Supported by National Institutes of Health,National Cancer Institute,No.R01 CA188654 and No.R01CA154451
文摘BACKGROUND The robust fibroinflammatory stroma characteristic of pancreatic ductal adenocarcinoma(PDA)impedes effective drug delivery.Pulsed focused ultrasound(pFUS)can disrupt this stroma and has improved survival in an early clinical trial.Non-invasive methods to characterize pFUS treatment effects are desirable for advancement of this promising treatment modality in larger clinical trials.AIM To identify promising,non-invasive pre-clinical imaging methods to characterize acute pFUS treatment effects for in vivo models of PDA.METHODS We utilized quantitative magnetic resonance imaging methods at 14 tesla in three mouse models of PDA(subcutaneous,orthotopic and transgenic-KrasLSLG12D/+,Trp53LSL-R172H/+,Cre or“KPC”)to assess immediate tumor response to pFUS treatment(VIFU 2000 Alpinion Medical Systems;475 W peak electric power,1 ms pulse duration,1 Hz,duty cycle 0.1%)vs sham therapy,and correlated our results with histochemical data.These pFUS treatment parameters were previously shown to enhance tumor permeability to chemotherapeutics.T1 and T2 relaxation maps,high(126,180,234,340,549)vs low(7,47,81)b-value apparent diffusion coefficient(ADC)maps,magnetization transfer ratio(MTR)maps,and chemical exchange saturation transfer(CEST)maps for the amide proton spectrum(3.5 parts per million or“ppm”)and the glycosaminoglycan spectrum(0.5-1.5 ppm)were generated and analyzed pre-treatment,and immediately post-treatment,using ImageJ.Animals were sacrificed immediately following post-treatment imaging.The whole-tumor was selected as the region of interest for data analysis and subsequent statistical analysis.T-tests and Pearson correlation were used for statistical inference.RESULTS Mean high-b value ADC measurements increased significantly with pFUS treatment for all models.Mean glycosaminoglycan CEST and T2 measurements decreased significantly post-treatment for the KPC group.Mean MTR and amide CEST values increased significantly for the KPC group.Hyaluronic acid focal intensities in the treated regions were significantly lower following pFUS treatment for all animal models.The magnetic resonance imaging changes observed acutely following pFUS therapy likely reflect:(1)Sequelae of variable degrees of microcapillary hemorrhage(T1,MTR and amide CEST);(2)Lower PDA glycosaminoglycan content and associated water content(glycosaminoglycan CEST,T2 and hyaluronic acid focal intensity);and(3)Improved tumor diffusivity(ADC)post pFUS treatment.CONCLUSION T2,glycosaminoglycan CEST,and ADC maps may provide reliable quantitation of acute pFUS treatment effects for patients with PDA.
